This invention relates to a printing apparatus, and more particularly to a comma printing mechanism for a printer adapted for use with a table electronic calculator or the like.
Printers of one type known in the art comprise a plurality of type wheels, a plurality of selectors each adapted to cause one of the type wheels to stop in a desired position, a plurality of trigger claws each adapted to normally maintain one of the selectors in an inoperative position and to release the same from its inoperative position to cause the selector to interrupt the movement of the associated type wheel, a plurality of electromagnets each provided with an actuator for controlling the operation of one of the trigger claws, and a platen adapted to move relative to the type wheels during the printing process.
Many printers of the aforementioned type are not provided with a comma printing mechanism. Printers employing a comma printing mechanism typically use one of two known methods. In one type of prior art comma printing mechanism a fixed decimal point is inserted, and commas or spaces between the digits are then located at positions determined by the fixed decimal point. In a second type of comma printing mechanism, a decimal point is moved for each set of three digit positions, and fixed comma positions are maintained. Thus, the prior art comma printing mechanisms lack flexibility, as they are not capable of placing a comma in any desired position.